An existing cell mobile communication system, as shown in FIG. 1, consists mainly of a Core network (CN), a Radio Access Network (RAN) and a terminal. The CN holds responsibility for non-access stratum services such as update of terminal location and the like, and the CN is an anchor for the user plane. The RAN includes a base station or includes a station and a base station controller, and the RAN holds responsibility for access stratum services such as management of radio resources; physical or logical connections may exist, according to practical conditions, between base stations, for example connections between base station 1 and base station 2 or base station 3, as shown in FIG. 1; moreover each base station can be connected to one or more CN nodes. The terminal, i.e., User Equipment (UE), refers to various equipments that can communication with the cell mobile communication network, such as a mobile phone, a laptop computer and the like.
Specifically, the CN includes mainly the following network elements:
SMS Service Center (SMS-SC), which generates the content of an SMS message and package it as an SMS data packet according to an SMS protocol;
SMS Gateway Mobile Switching Center (SMS-GMSC), which receives an SMS data packet transmitted by the SMS-SC, reads and checks parameters in the SMS data packet, queries a Home Subscriber Server (HSS) for routing information of the terminal, which herein refers to identifiers of a Mobile Switching Center (MSC) and a Mobility Management Entity (MME) via which the SMS message is transmitted;
HSS, which stores subscription information of each subscriber, and information of a serving node, for example an identifier of a serving node (MSC or MME) that provides the terminal with services;
MSC, which is a core network entity responsible for providing, in a circuit switched network, the terminal with services including control signaling transmission, SMS message transmission and mobility management;
MME, which is a core network entity responsible for providing, in a packet switched network, the terminal with services including control signaling transmission, SMS message transmission and mobility management; and
MTC Inter Working Function (MTC-IWF) entity, which is a connection entity between a mobile communication network and an external public network and can implement functions such as protocol conversion, address query and information storage.
An External Identifier (EID) of a terminal refers to an identifier used by the terminal beyond a mobile communication network, and the EID should be globally unique and include following two portions:
1. an Domain Identifier (DID), which identifies a domain controlled by a mobile network operator, the domain is use to identify an access address of a service provided by the operator's network, such as a service provided by MTC-IWF, and the operator may use different DIDs to provide different service accesses;
2. a Local Identifier (LID), which is an identifier used to acquire an International Mobile Subscriber Identity (IMSI) of a terminal and managed by a mobile network operator, and which is unique within its applied scope.
Each terminal has only one IMSI but one or more EIDs, that is to say, one IMSI of a terminal corresponds to one or more EIDs. In the prior art, after receiving a triggering request from an MTC server, a terminal is desired to respond immediately and establish a connection with the MTC server; however, for a terminal having multiple EIDs, when the terminal responds to the MTC server and requests to establish the connection with the MTC server, a network side cannot distinguish between different EIDs, thus the network side may respond erroneously to the triggering request from the MTC server, that is to say, the network side cannot use a correct EID to respond to the triggering request from the MTC server.
On the other hand, in the prior art, a destination address (TP-DA) parameter in a Transmission Protocol Data Unit (TPDU) of an SMS message is written as a Mobile Subscriber ISDN (MSISDN) number of the terminal at an SMS-SC, where the ISDN stands for Integrated Service Digital Network. Then during MSISDN-less communications, other terminal identifiers are needed to replace the MSISDN number. In existing solutions, the TP-DA parameter is directly written as an IMSI, however excessive exposure of an authentic IMSI of a terminal to an network will inevitably result in potential security hazards to the terminal.